add a test

tests/integration-tests/load-save/abis/Contract.abi

@@ -0,0 +1,33 @@
+[
+  {
+    "inputs": [],
+    "stateMutability": "nonpayable",
+    "type": "constructor"
+  },
+  {
+    "anonymous": false,
+    "inputs": [
+      {
+        "indexed": false,
+        "internalType": "uint16",
+        "name": "x",
+        "type": "uint16"
+      }
+    ],
+    "name": "Trigger",
+    "type": "event"
+  },
+  {
+    "inputs": [
+      {
+        "internalType": "uint16",
+        "name": "x",
+        "type": "uint16"
+      }
+    ],
+    "name": "emitTrigger",
+    "outputs": [],
+    "stateMutability": "nonpayable",
+    "type": "function"
+  }
+]

tests/integration-tests/load-save/package.json

@@ -0,0 +1,25 @@
+{
+  "name": "load-save",
+  "version": "0.1.0",
+  "scripts": {
+    "build-contracts": "../../common/build-contracts.sh",
+    "codegen": "graph codegen --skip-migrations",
+    "test": "yarn build-contracts && truffle test --compile-none --network test",
+    "create:test": "graph create test/load-save --node $GRAPH_NODE_ADMIN_URI",
+    "deploy:test": "graph deploy test/load-save --version-label v0.0.1 --ipfs $IPFS_URI --node $GRAPH_NODE_ADMIN_URI"
+  },
+  "devDependencies": {
+    "@graphprotocol/graph-cli": "0.69.0",
+    "@graphprotocol/graph-ts": "0.34.0",
+    "solc": "^0.8.2"
+  },
+  "dependencies": {
+    "@truffle/contract": "^4.3",
+    "@truffle/hdwallet-provider": "^1.2",
+    "apollo-fetch": "^0.7.0",
+    "babel-polyfill": "^6.26.0",
+    "babel-register": "^6.26.0",
+    "gluegun": "^4.6.1",
+    "truffle": "^5.2"
+  }
+} 

tests/integration-tests/load-save/schema.graphql

@@ -0,0 +1,5 @@
+type LSData @entity {
+  id: ID!
+  data: String!
+  blockNumber: BigInt!
+} 

tests/integration-tests/load-save/src/mapping.ts

@@ -0,0 +1,17 @@
+import { BigInt, ethereum } from '@graphprotocol/graph-ts'
+import { LSData } from '../generated/schema'
+
+export function handleBlock(block: ethereum.Block): void {
+  let diff = 1
+  let entity = new LSData(block.number.toString())
+  entity.data = 'original entity'
+  entity.blockNumber = block.number
+  entity.save()
+  let block_number = block.number
+  if (block_number.gt(BigInt.fromI32(diff))) {
+    let bn = block_number.minus(BigInt.fromI32(diff)).toString()
+    let entity2 = LSData.load(bn)!
+    entity2.data = 'modified entity'
+    entity2.save()
+  }
+}

tests/integration-tests/load-save/subgraph.yaml

@@ -0,0 +1,25 @@
+specVersion: 1.2.0
+description: Source Subgraph A
+repository: https://github.com/graphprotocol/graph-node
+schema:
+  file: ./schema.graphql
+dataSources:
+  - kind: ethereum/contract
+    name: SimpleContract
+    network: test
+    source:
+      address: "0x5FbDB2315678afecb367f032d93F642f64180aa3"
+      abi: SimpleContract
+      startBlock: 0
+    mapping:
+      kind: ethereum/events
+      apiVersion: 0.0.6
+      language: wasm/assemblyscript
+      entities:
+        - LSData
+      abis:
+        - name: SimpleContract
+          file: ./abis/Contract.abi
+      blockHandlers:
+        - handler: handleBlock
+      file: ./src/mapping.ts 

tests/tests/integration_tests.rs

@@ -603,6 +603,19 @@ async fn subgraph_data_sources(ctx: TestContext) -> anyhow::Result<()> {
     Ok(())
 }
 
+async fn load_save(ctx: TestContext) -> anyhow::Result<()> {
+    let subgraph = ctx.subgraph;
+    assert!(subgraph.healthy);
+
+    let _contract = ctx
+        .contracts
+        .iter()
+        .find(|x| x.name == "SimpleContract")
+        .unwrap();
+
+    Ok(())
+}
+
 async fn test_topic_filters(ctx: TestContext) -> anyhow::Result<()> {
     let subgraph = ctx.subgraph;
     assert!(subgraph.healthy);
@@ -980,6 +993,7 @@ async fn integration_tests() -> anyhow::Result<()> {
         TestCase::new("block-handlers", test_block_handlers),
         TestCase::new("timestamp", test_timestamp),
         TestCase::new("ethereum-api-tests", test_eth_api),
+        TestCase::new("load-save", load_save),
         TestCase::new("topic-filter", test_topic_filters),
         TestCase::new_with_source_subgraph(
             "subgraph-data-sources",